The 3GPP (3rd Generation Partnership Projection) Evolved Packet System (EPS) consists of the Evolved UMTS Terrestrial Radio Access Network (EUTRAN) and Evolved Packet Core (EPC). The EPC, which consists of Mobility Management Entities (MMES), Serving gateways (GWs) and Packet Data Network GWs (PDN GWs), is mainly responsible for management of mobility, processing of Non-Access-Stratum, and EPS bearer resource control and other related works.
EPS bearer is a logic aggregate of one or more service data streams, and is located between user equipment (UE) and PDN GW. When the UE does data services after attaching to the core network, it will obtain bearer resources required for the services by initiating a bearer resource allocation procedure. The EPC will allocate a bearer resource conforming to the current service for the UE according to a bearer level QoS (Quality of Service) parameter and Traffic Flow Template (TFT) carried in a request message sent by the UE in the procedure.
The UE initiates the bearer resource allocation procedure to the EPC to trigger the EPC to initiate a proprietary bearer activation procedure or proprietary bearer modification procedure to the UE. Currently, in the prior art there are the following several technical schemes for a decision mechanism for triggering the proprietary bearer activation or proprietary bearer modification:
Scheme 1: only the proprietary bearer activation procedure is triggered, and the current bearer resource allocation request of the UE is rejected once a bearer upper limit is reached.
Scheme 2: the EPC firstly searches for the local bearer context associated with the UE. If there is a bearer corresponding to a QCI (QoS Class Identifier) consistent with a QCI carried in a bearer resource allocation request message sent by the UE, the EPC initiates a proprietary bearer modification procedure; otherwise, the EPC initiates a proprietary bearer activation procedure.
The following problems mainly exist in the decision schemes described above:
Scheme 1: resource waste is caused easily; once a bearer is established, the bearer will be always occupied, whether there is data transmission or not. Thus, when the number of bearers reaches the upper limit, initiation of new services will not be accepted, thereby reducing the utilization ratio of system resources.
Scheme 2: the EPC will firstly search for the bearer context whenever it receives the bearer resource allocation request, which inevitably increases the processing delay of the system itself, and decreases the response speed of the system to the service.